diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index d4cd7f349a..c2131445a1 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -764,6 +764,7 @@ def check_tmpdir
 end
 
 def check_missing_deps
+  return unless HOMEBREW_CELLAR.exist?
   s = Set.new
   missing_deps = Homebrew.find_missing_brews(Homebrew.installed_brews)
   missing_deps.each do |m|